Answer:
(A) option A is correct that is draw TV so that V is the mid point of SU, then prove ΔSTV≅ΔUTV using SSS.
Explanation:
From the given figure, it is given that ST=TU, then draw TV so that V is the mid point of SU, then, from
ΔSTV and ΔUTV
ST=UT (Given)
SV=UV (Definition of mid point)
TV=TV (Reflexive property)
Thus, by SSS rule
ΔSTV≅ΔUTV
Hence, by CPCTC, ∠S≅∠U which satisfies the isosceles triangle theorem that is "If two sides of a triangle are congruent then the angles opposite those sides are congruent".
Thus, option A is correct that is draw TV so that V is the mid point of SU, then prove ΔSTV≅ΔUTV using SSS.